Jewelry rope chains are formed from individual links made of wire with the various links being tightly interfit one into the other so as to be intertwined and fit one against the other to form an outward appearance of a double helix. The links generally have a small gap formed within their periphery to enable one of the other links to pass through the gap. A number of links are interconnected in accordance with particular ratios and thereafter a group is formed together. A new group is then begun interconnected to the old group and again the group is repeated.
The particular formation of the rope chain has become quite sophisticated and numerous improvements have been made in order to reduce the amount of gold required in the formation of the rope chain and yet obtain an acceptable outer appearance. Historically, the links were typically of circular configuration having an inner and outer diameter with a gap formed in the circumference. The links typically form the shape of an annulus such as a tire.
Typically, the ratio of the inner diameter of the link annulus to the diameter of the wire forming the link was of a ratio slightly greater than three. In such situations, three of such links were interfit one into the other and then a fourth link intertwined the other three.
U.S. Pat. No. 4,651,517 to Benhamou, et al. described a method of reducing the amount of gold by increasing the ratio from the 3:1 ratio to an odd ratio of 5:1 and greater. In such cases, the ratio of the inner diameter of the link annulus to the wire diameter forming the link was thus slightly greater than 5:1. Thus, five individual links would be intertwined and a sixth would be intertwined with the original five, thereby forming a group.
Although typically an odd number of links were utilized for each group with one additional one intertwining them, U.S. Pat. No. 4,934,135 to Rozenwasser describes the use of an even number of links with an even ratio.
While generally circular shaped links have been used, U.S. Pat. No. 4,996,835 to Rozenwasser showed that elliptical shaped links and other geometric configurations could also be utilized. Additionally, chains using other link configuration have been known such as those shown in Design Patents 340,422 and 343,136 issued to Grando, and Design Patent 321,148 issued to Chiaramonti, et al. Many other types of geometric shaped links have also been suggested.
The particular shape of the wire utilized to form the link has also varied over the years. While historically circular cross sectional wire had been used, numerous other configurations have been shown such as those in U.S. Pat. No. 5,185,995 to Dal Monte as well as the rectangular cross sectional configuration shown in U.S. Pat. No. 5,361,575 to Rozenwasser, and others.
The particular wire utilized to form the link can either be solid wire or hollow wire. In the case of hollow wire, the wire can either be with an open channel or seam along the inner periphery of the link or it can be without the seam or channel. The use of the seam or channel is to permit melting out of the material used to fill the hollow center of the wire during its formation into a hollow wire for use in the formation of the individual links.
In order to improve the appearance of the rope chain, there has been introduced the idea of shaving or cutting a portion of the exterior surface of the rope chain in order to provide what is generally referred as a diamond cut faceted rope chain. When dealing with solid wire in forming the links, the rope chain is then referred to as a solid rope chain. In such cases, it is relatively easy to provide the facets. As the wire is solid, there is no problem in shaving off a portion of the wire to change the external configuration of a round shape to a flat facet. Typically, the solid wire rope chain is passed longitudinally through a series of cutting blades which cut the exterior along a fixed number of sides. Usually, it is cut along four sides to provide a square like configuration with the four sides being cut. However, other shapes, such as hexagonal, can also be formed with a diamond cut configuration.
When dealing with rope chain formed of hollow wire, the rope chain is referred to as a hollow rope chain. In such cases, it had been difficult if not impossible to achieve diamond cut facets on the rope chain. Utilizing the same shaving or cutting technique as is used for solid rope chain would cut into the wire itself. Because the wire is only of a thin wall construction, cutting a portion of that hollow wire tubing would cut through the wall and penetrate it. Since, the depth of cut is greater than the thickness of the wall.
In order to achieve a simulated diamond cut, it had been suggested in U.S. Pat. Nos. 5,125,225 and 5,129,220 issued to Strobel, to deform the exterior surface wall of the hollow rope chain to provide to simulated diamond cuts. These patents describe initially forming a hollow rope chain and then wrapping the rope chain around a mandrel and freezing the chain. Thereafter, a pounding action is provided against the exterior wall of the rope chain along four or six sides, to flatten or deform the exterior wall of the rope chain along these sides. Thus, the hollow exterior wall of the wire is depressed inwardly toward the interior wall of the wire so as to flatten the wire itself.
Another approach to achieving diamond cut facets on a hollow rope chain is described in U.S. Pat. No. 5,285,625 issued to Orfat, et al. While the heretofore described Strobel patents provided simulated diamond cuts along four or six sides, the Orfat patent describes a spiral facet which is formed around the periphery of the rope chain in a spiral configuration. The facets formed in Strobel are only on four sides and provided a substantially square, or hexagonal cross sectional configuration to the chain. The facets formed by Orfat provide a substantially circular cross sectional configuration.
Another approach to providing facets in hollow rope chain is described in U.S. Pat. No. 5,303,540 to Rozenwasser which provides a shallow band or strip extending along the surface of at least a part of the outer perimeter of the link to give a diamond cut appearance to the rope chain.
While these suggested approaches to achieving a diamond cut hollow rope chain have been useful, there is still a need for an efficient method of producing such diamond cut rope chain and which permits the ability of providing the exterior shape of the rope chain as desired.
Furthermore, it would also be desirable to give greater control to the manufacturer to reshape the exterior of a rope chain, not only to produce facets, but to provide any desired shape to the exterior.